Use unless loop for comma

and mention `search_exclude`

docs/search.md

@@ -37,13 +37,13 @@ This command creates the `search-data.json` file that Jekyll uses to create your
 {% raw %}---
 ---
 {
-  {% for page in site.html_pages %}"{{ forloop.index0 }}": {
+  {% for page in site.html_pages %}{% if page.search_exclude != true %}"{{ forloop.index0 }}": {
     "id": "{{ forloop.index0 }}",
     "title": "{{ page.title | xml_escape }}",
     "content": "{{ page.content | markdownify | strip_html | xml_escape | remove: 'Table of contents' | remove: page.title | strip_newlines | replace: '\', ' '}}",
     "url": "{{ page.url | absolute_url | xml_escape }}",
     "relUrl": "{{ page.url | xml_escape }}"
-  }{% if forloop.last %}{% else %},
+  }{% unless forloop.last %},{% endunless %}
   {% endif %}{% endfor %}
 }{% endraw %}
 ```